# US 2014/0191750 A1 · Sensor for locating metal objects and associated coil > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2014/0191750 A1 - Document ID: US20140191750A1 - Status: Published application - Kind: A1 - Application number: 14/237,945 - Filed: 2012-08-03 - Published: 2014-07-10 - Earliest claimed: 2011-08-10 - Inventors: Gerd Reime - Web page: https://patentgrep.com/patent/US20140191750A1 ## CPC - G01B 7/14: for measuring distance or clearance between spaced objects or spaced apertures (G01B7/30 takes precedence) - G01N 27/72: by investigating magnetic variables - G01V 3/107: {using compensating coil or loop arrangements} - G01B: MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS - G01N: INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES (measuring or testing apparatus or processes other than immunoassay, involving enzymes or microorganisms C12M, C12Q) - G01V: GEOPHYSICS; GRAVITATIONAL MEASUREMENTS; DETECTING MASSES OR OBJECTS; TAGS (means for indicating the location of accidentally buried, e.g. snow-buried, persons A63B29/02) ## Abstract A sensor for locating metal objects has coils or coil parts which form at least one transmitting coil (5.1) and at least one receiving coil (7.1) which are inductively coupled to one another and are arranged such that said coils partially overlap for the purpose of interaction decoupling, wherein optimum cancellation of the interaction can be achieved. Sensor electronics are provided for energizing the transmitting coil and for evaluating a reception signal (10.6) from the receiving coil. As a result of the fact that the transmitting coil (5.1) and the receiving coil (7.1) substantially have an identical coil shape and are arranged such that said coils are rotated and/or offset with respect to one another, wherein a plurality of symmetrically arranged, overlapping regions (8.4) are formed, a sensor which provides a greater range and extended possibilities for installation in conventional industrial sensor housings is provided. ## Claims ### Claim 1 A sensor for locating metal objects, comprising: coils or coil parts that form at least one transmitting coil and at least one receiving coil, which are inductively coupled to one another and are arranged to partly overlap for the purpose of decoupling interaction, wherein an optimal cancellation of the interaction may be achieved, and a sensor electronics unit for supplying current to the transmitting coil and for analyzing a receiving signal from the receiving coil, wherein the transmitting coil and the receiving coil have a substantially identical coil shape and are rotated and/or offset in relation to one another, wherein a plurality of symmetrically arranged overlap regions are formed, wherein the coil shape has loop portions that are meandering and arranged along a periphery of the coil or coil parts, wherein the loop portions have portions, which are arranged to have differing radial spacings from a centre point of the coil, and are connected alternately to one another to form an electrical conductor. ### Claim 2 (depends on 1) A sensor according to claim 1, wherein the overlap regions are arranged to have point symmetry in relation to the center of the coils. ### Claim 3 (depends on 1) A sensor according to claim 1, wherein the coil or coil parts are planar and wherein the loop portions are each part of a winding of the coil or coil part. ### Claim 4 (depends on 1) A sensor according to claim 1, wherein the coil is circular and has n loop portions, wherein the loop portions of the transmitting coil and the receiving coil are arranged rotated about an angle of approximately 360°/(n*2). ### Claim 5 (depends on 1) A sensor according to claim 1, wherein the loop portions have circular portions at the differing radial spacings and are connected alternately to one another, by way of radially arranged portions, to form the electrical conductor. ### Claim 6 (depends on 1) A sensor according claims 1, wherein a plurality of transmitting coils and at least one receiving coil are provided. ### Claim 7 (depends on 1) A sensor according to claim 1, in that wherein field lines of a field that is inverted in relation to the field lines caused by a supply of current to the transmitting coil are formed within inwardly open loop portions of the receiving coil, while a field that acts in the same direction as the field lines of the transmitting coil is formed in an interior of the receiving coil. ### Claim 8 (depends on 1) A sensor according to claim 1, wherein the periphery of the transmitting coil is approximately almost congruent with the periphery of the receiving coil. ### Claim 9 (depends on 1) A sensor according to claim 1, wherein a comparator is provided for comparing current signals that are associated with the transmitting coils in order to determine a control value, and in that at least one regulated current source is provided in which a control value for regulating an amplitude of current supplied to the transmitting coil continuously regulates the amplitude such that amplitudes of voltage signals at inputs of the comparator are of the same size, or that there is no difference in the voltage signals at the inputs of the comparator from both clock portions of a clock cycle. ### Claim 10 A coil for use in a sensor for locating metal objects as a receiving coil and/or as a transmitting coil, wherein loop portions that are meandering are provided along a periphery of a planar coil and are each part of a coil winding, wherein the loop portions have portions which are arranged to have differing radial spacings from a centre point of the coil, and are connected alternately to one another to form an electrical conductor. ### Claim 11 (depends on 10) A coil according to claim 10, wherein the loop portions are formed by circular portions arranged to have at the differing radial spacings from the centre point of the circular coil, and are connected by way of radially arranged portions, to form the electrical conductor.